Chapter 10, Lesson 1

​Chapter 10, Lesson 1

Acceleration​

Pages 368-373

​As you work through this lesson, WRITE down the underlined vocabulary terms. Your score will be recorded in Progressbook, please retake this until you are happy with your score.

Use pages ​368-373 in your book if you need more details

What is acceleration?

Typically, we think of acceleration as the process of speeding up

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Acceleration - the rate at which velocity changes

Three ways to accelerate:

• speed up

• slow down (deceleration = negative acceleration)

• change direction​

​Sketch this into your notes.

Videos

Go to the links below and watch the videos

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https://youtu.be/Jyiw6KkedDY

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https://youtu.be/J3SdZwMcWhA​

Multiple Choice

When a car goes around a corner at 20mph, why do we say it accelerates?

• because the velocity is constant

• because it is going 20mph

• Cars always accelerate when they are in motion

• because it is changing direction

Multiple Choice

Acceleration only takes place when things speed up.

• true

• false

Multiple Choice

Which of the following is accelerating?

• a ball that picks up speed as it rolls down the hill

• a car that brakes to a stop to avoid a crash

• a racecar that travels around a curve at a constant speed

• all of these are examples of acceleration

Soccer Ball Physics

Reference Point - the motion of an object is always measured with respect to another object.

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In soccer (or any sport), the lines on the field/court can be used as reference points​ - the reference point (the lines) do not move compared to the object being observed (the ball)

Calculating Acceleration

Acceleration is the rate that velocity is changing

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Acceleration = ​(final speed - initial speed)/time

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Objects that are accelerating cover more distance with each passing second​

Open Ended

Why would you land much harder if you jumped off of a 6 meter building than a 1 meter fence? EXPLAIN YOUR ANSWER!

Deceleration (Negative Accelerations)

Deceleration - slowing down

• velocity is still changing

• changing velocity is ACCELERATION!

• use the same formula

• when calculating ACCELERATION for an object that is slowing down, you will always get a NEGATIVE ANSWER​

Fill in the Blanks

A softball has a (positive/negative) acceleration when it is thrown.

Fill in the Blanks

A softball has a (positive/negative) acceleration when it is caught.

Open Ended

A girl skates around the perimeter of a circular ice rink at a constant speed of 2 m/s. Is she accelerating? EXPLAIN your answer.

Graphing Acceleration

• Acceleration can be graphed as distance versus time OR speed versus time​

• If an object is stopped it would be graphed as a straight, horizontal line on a DISTANCE versus time graph​

• If an object has zero acceleration (it is travelling at a constant rate) it would also be graphed as a straight, horizontal line on a SPEED versus time graph​

Graphing Acceleration

• The SPEED versus time graph for an object with a constant acceleration would be a straight line

• The DISTANCE versus time graph of an object that is accelerating (speeding up or slowing down) would be curved

Open Ended

If the distance versus time graph of an object's motion is a straight line, could the object be accelerating? EXPLAIN.

Open Ended

Could an object with a curved graph have zero acceleration? EXPLAIN.

Multiple Select

In science, what THREE changes can each cause an object to accelerate?

• speed up

• move at a constant speed

• change direction

• slow down

Multiple Choice

If a train is slowing down, it is accelerating.

• true

• false

Multiple Choice

To find the acceleration of an object moving in a straight line, you must calculate the change in distance for each unit of time.

• true

• false

Multiple Choice

A Ferris wheel turning at a constant speed of 5 m/s is not accelerating.

• true

• false

Multiple Choice

A speed versus time graph for a car's motion is a horizontal line at a speed of 12 m/s. The car's acceleration during this time is 12 m/s².

• true

• false

Fill in the Blanks

The rate at which the velocity of an object changes is the object's rate of

.

Make sure you spell correctly.

​Once you have a score that you are satisfied with, you should complete 8th grade science IXL lessons G.6, G.7, G.8, G.9, and G.10

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I have left a copy of the IXL log ins with the sub if you don't know your log in​